We demonstrate chirped-pulse operation of a Cr : YAG passively mode-locked laser. Different operation regimes of the laser are extensively investigated in the vicinity of zero dispersion both experimentally and numerically. It is shown that for a given laser configuration, transition to the positive dispersion regime allows a 5-fold increase in the output pulse energy, which is otherwise limite...

This work studied the effect of additions of carbon dioxide to argon shielding gas on the weld shape and microstructure of ST14 steel in pulsed Nd: YAG laser welding. By additions of carbon dioxide up to 15%,the weld area and depth/width ratio decreases while rising of carbon dioxide up to 25% causes increasing of weld area and depth/width ratio. It is observed that the weld metal microstructur...

We report on the first observation of low temperature pulsed blue and orange laser emissions in P~~+:YAG. Furthermore, we compare these results with similar observations in YLiF4 and YAlO3 doped crystals. Pulsed laser oscillations were obtained in crystals with uncoated surfaces by direct excitation of one of the relevant Stark components of the PO, 3 ~ 1 or 3 ~ 2 states. A careful1 spectroscop...

objective: the aim of this study was to evaluate and compare the effect of dental surface treatment with er:yag , nd:yag ,co2 lasers and sodium ascorbate to recently laser bleached enamel by scanning electron microscope (sem). methods: 15caries-free extracted human third molars were selected for this study. the samples were bleached by heydent jw power activated by diode laser 810 nm. after 7 d...

Three cases of malignant glaucoma following extracapsular cataract extraction with 7 mm one-piece posterior chamber intraocular lens implantation are presented. Nd-YAG laser hyaloidotomy was successfully performed in all eyes, but was difficult and required several sessions in two eyes. In the third eye, which had a sector iridectomy, laser hyaloidotomy applied over the edge of the lens optic t...

The present study was performed to understand the regeneration of the intralobular duct and acinus of partially injured salivary glands. Sections of rat submandibular glands irradiated with YAG laser were investigated histologically, and the proliferative activity of regenerating tissue was also investigated immunohistochemically with anti 5-bromo-2'-deoxyuridine (BrdU) monoclonal antibody. Aft...

We report a case of an epithelial inclusion cyst of the iris following cataract surgery that was successfully treated with en bloc excision, after an unsuccessful attempt with Neodymium-doped Yttrium Aluminium Garnet (Nd YAG) Laser. A 60-year-old man had undergone cataract surgery two years back. One year later, he developed a pigmented epithelial inclusion cyst of the iris which progressively ...